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| Just out of curiosity, what do most of you pay to have soil grid testing done in the fall? I have to give $16 dollars an acre, 2 1/2 acre grids. I do this every 4 years, usually on bean ground going into corn next year. |
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Central IL | Thats insane
I bet they give you free hat too!
Edited by wade garrett 10/15/2020 17:20
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mn | Thats WAY too much. I paid $6 last year. For $16 you could buy your own automatic sampler if you have any amount of acres. |
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39.48, -82.98 | $8 per sample, if you can pull them yourself. That works out to $3.20/acre at 2.5 acres per sample. |
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WC Mn/Dakotas | All depends on soil tests run and quantity and quality of the cores taken. You couldn't pay me to have someone grid that takes 1 core per sample by some intern chewing sunflower seeds and barely stopping the truck. In and out of 160 acres in an hour. Now someone taking quality, consistent cores and 10-12 per sample is completely different and will take 8 hours. Then some only test a few nutrients others do a complete analysis so thats $3/sample vs $31/sample. It all depends. I want quality whatever, or your just making it look good and wasting money. Junk in gets junk out more here than most anywhere. |
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| I would hope your not using square grids. We stopped doing that many years ago in favor of management zones (mainly soil types, topography, or better still... solid yield data that's normalized). |
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MN | If it takes you 8 hours to grid 160 acres "properly"...I'd suggest less coffee breaks. |
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Missouri | $10 for first sample, $8 for resample. 2.5 acre grids. I do nothing. He sends scripts to my person doing dry fertilizer. He’d load it for me to do it myself or someday when I start doing variable rate N also. |
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WC Mn/Dakotas | You dont get quality cores (results) fast. 160 acres at 2.5ac grids and 12 cores per sample is 768 cores. If you had 100% success good cores and you could take 1 core per min, that's 13 hours. The less time the more corners are cut. Then your going to make 4 years fert decisions and 4 years of crop based on less than the most accurate data? Ya thats cheap. |
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east central south dakota | Goose is 100% correct. Growers so worried about an extra $2-3 to do it right, instead can waste 100’s per acre with bad information. Phil I agree with your zone concept as well, we lean that way hard. I believe zone are great except where heavy manure has been applied. My preference is integrating zones with grids at that point. Quality will outlast the basic $6 test in the long run. Integrate what matters, physical+biological+chemical aspects of the soil. That is where the money is made. Knowing when and where to spend the money. Not spending more for the process then the data.
Edited by 123agscout 10/15/2020 19:16
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Southeast WI | Ah one of the most talked about issues on nat and everyone is consistently correct in how they do it so I'll defer to the experts. As to your question it depends what info you are getting and beyond that what you are or can do with it - guess we need more info from you on what's being provided. |
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Chebanse, IL..... | So we that use square grids are wrong? Or just different?
Is it better to wear anti-covid masks, or not wear them?
Is a CNH combine better than a JD combine? |
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| I'm just saying we started soil sampling with square grids in the mid 1990's, but we soon realized they didn't match the variables in most fields very well, so we transitioned to management zones.
For example, I have asked growers what features appear in "squares" on a yield map? Don't yield maps mostly feature polygons which are specifically related to soil type, drainage, topography, or other field specific features?
I'm just suggesting you draw your polygons around the variability contours and sample them separately and adjust the sizes of the management zones based on the variability in that area of the field (lots of variability = more regions, less variability = less regions).
Edited by Phil N 10/15/2020 21:28
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indiana | How many ounces in a core ? Sounds like you are hauling out one heck of a lot of soil ! LoL |
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indiana | Nothing wrong with fine tuning , it usually returns nice dividends. 2.5 ac square grids work here. |
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| GOOSEPILOT - 10/15/2020 19:02
You dont get quality cores (results) fast. 160 acres at 2.5ac grids and 12 cores per sample is 768 cores. If you had 100% success good cores and you could take 1 core per min, that's 13 hours. The less time the more corners are cut. Then your going to make 4 years fert decisions and 4 years of crop based on less than the most accurate data? Ya thats cheap.
Yep. Cheaper ain't always better. We decided to do our own too. Heck, it can't be a big deal right? A guy on a 4 wheeler rolls through here, and can do most of 1000 acres in a day. He is on an off that four wheeler so fast, and gone before you know he was there. Doing it right was much, much more time consuming as Goose suggested. And what do you know, the variability in the samples disappeared too.
Take care
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Chebanse, IL..... | Here....
For a little less than $7 per acre we get....
2.5 acre square grids (gps).
Basic tests, Ph, P, K, OM, CEC. No micros
4 year cycle
Annual visits with annual recommendations.
Prescription files for spreader based on annual visit recommendations.
We have been with the same guy for about 15 years. We started square grid testing in 1975. Back then a husband/wife team did testing & there weren't color printers. They used graph paper & colored pencils to make maps. We've been grid testing for 45 years.
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Donnellson, IA. Makes saying here easier. | +1 on zones. And definitely do my own samples. I have seen some really awesome displays of quick soil sampling. Then again most here only use them for lime recs and run the same crop removal program the always have. I get more people to test for extra nutrients each year, and they are happy with the results as we address more deficiencies. |
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ECIL | Interesting discussion. I would challenge people to do this experiment. Go to what you think is a random spot in your field. Take 13 core samples in the shape of a cross 2 ft apart one in the center and 3 on each side. Test the individual core samples. Don't tell the lab what you are doing. You will learn a lot. |
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Northern Nebraska | Where can you get soil tested for $8? |
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Manitoba | Seeing lots of debate over grids vs zones here, both have good and both have serious downfall. A square grid (composite of each square block is garbage), a site specific grid is accurate at each sample but loses accuracy to statistics between point the larger the grid size. Zones show a nice pattern you may be used to seeing in soil types or yield but that doesnt mean thats how your nutrients vary, all zones make a map without any nutrient data and then soil sample and apply nutrient data to it later. So you do not get any nutrient maps with a zone sample.
We have gone to Soil OPtix the last 4 years which gives the best of zones and grids. It uses site specific points (1 per 6 ac) placed based on the soil variability and the mapping gives us the rate of change for each layer INDEPENDANTLY as well as topography because where water flows makes a big difference. With this system we have a data point roughly every 10 ft fully stacked with soil test data. 40+ maps instead of 1 map like a zone system and I have never seen a field where more than a couple of those layers looked similar.
We did a 1/2 ac site specific grid to verify the data on multiple 160 ac fields and were amazed at how accurate the data was.
I attached a demo field if anyone wants to take a look, we do this western canada there may be providers that can come to your area but I dont know. We have set legends for the maps that we can so that a grower can compare all his fields on an even scale as well as to his friends. That is why there is an extra P map for this field because the P was very high that it was all at the top end of the scale.
That is another thing to always watch, legend can be adjusted to show lots of variability when there really isnt any, our sulphur maps can do this because S can vary so much the legend it set to put the full range of colours to whatever range is there, it can be 10 ppm or 300.
Edited by blyth12 10/16/2020 07:28
 (Optix Resolution (full).jpg)
Attachments
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 Optix Resolution (full).jpg (101KB - 170 downloads)
demo wetness 3d ab.pdf (353KB - 256 downloads)
demo wasted fertilizer ab3.pdf (289KB - 267 downloads)
demo texture ab.pdf (137KB - 191 downloads)
demo phos ab.pdf (335KB - 282 downloads)
demo optix map with ratios ab2.pdf (5631KB - 324 downloads)
demo opt boron ab4.pdf (372KB - 198 downloads)
demo clubroot risk ab4.pdf (313KB - 200 downloads)
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Northern Nebraska | It's not wrong to use Square just not perfect. Is soil layed out in grids? Nope. It's got all sorts of different shapes that curve around physical features of the land. You can't just take one sample per zone either they should be broken down further.
It is scientifically and empirically proven you can wear a mask to stop the spread of disease.
Since deere went to a rotor they are essentially the same machine.
Edited by Hilltop Husker 10/16/2020 08:09
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Wallis, TX | kfrem - 10/15/2020 16:50
Just out of curiosity, what do most of you pay to have soil grid testing done in the fall? I have to give $16 dollars an acre, 2 1/2 acre grids. I do this every 4 years, usually on bean ground going into corn next year.
$10-10.50 for 2 acre grids. |
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WC Mn/Dakotas | garyl - 10/16/2020 07:14
Interesting discussion. I would challenge people to do this experiment. Go to what you think is a random spot in your field. Take 13 core samples in the shape of a cross 2 ft apart one in the center and 3 on each side. Test the individual core samples. Don't tell the lab what you are doing. You will learn a lot.
What is that going to prove? Have you been to your soil lab?
My answer is likely your inability to take consistent cores. Most variability comes from soil sampling, not from lab variability. Yes there is some lab variability, but most test for that regularly (again have you been to your lab?). The reason for higher core counts is to help eliminate variability of uneven nutrient from application (bcast or banded) and mechanical incorporation, or previous plant residue.
One core is not representative of a sample. Thats my whole point. The more cores you take, the more statistically accurate the sample is. Statistically, the accuracy curve really starts to taper off around 9 cores and much more so in the 12-16 core count, and pretty much flat at around 24 cores.
Less than 9 cores per sample is highly variable results imho. 12 cores from the JCB probes i use fill a bag to the middle of the sample bag full line and is a reasonable amount of time to get. I want to avoid manually mixing and then only submitting part of the soil collected because that leaves the door wide open to human errors too. 0-6" sample means you submit 6.0" cores, not 5.75" or 6.25" cores.
JCM probe not JCB
Edited by GOOSEPILOT 10/16/2020 08:32
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ECIL | What’s it going to prove? Nothing but it gives you another data set.
Have I visited with soil test lab owners and operators? Yes
Do I know how to run a soil probe good enough to collect 13 consecutive samples? I think so.
If I was wanting to check lab accuracy I would sent 1 know sample
Statistical relevance depends on the consistency of what your sampling also
Edited by garyl 10/16/2020 09:28
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WC Mn/Dakotas | garyl - 10/16/2020 07:14
Interesting discussion. I would challenge people to do this experiment. Go to what you think is a random spot in your field. Take 13 core samples in the shape of a cross 2 ft apart one in the center and 3 on each side. Test the individual core samples. Don't tell the lab what you are doing. You will learn a lot.
What’s it going to prove? Nothing but it gives you another data set.
Whats your challenge?
What is the purpose of this data set?
"If I was wanting to check lab accuracy I would sent 1 know sample"
Why then would you not tell the lab what your doing if your not checking them?
"You will learn alot"- what are you referring to?
"Statistical relevance depends on the consistency of what your sampling also."
I agree, that is precisely why you take more cores than less. Thats why you create very detailed zones to direct where you sample. |
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| We tested a field in 2.5 acre grids about 3 years ago, then came back and zone tested it last year. We were amazed how much variability there was within the zones that we never would have seen except when we looked at the map showing the grids within each zone.
We also discussed how there were only 3 zones in the 57 acre field and if my memory is correct about 20 grids. So the total number of times the probe was actually pushed into the ground was about 5 to 7 times greater with the grids. So right or wrong we decided to continue with grid sampling for the time being.
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Chebanse, IL..... | KS-Notill
This has been our experience also. Again, this may be a "here" thing. But let's say we have a 1/4 mi x 1/2 mi straight edge 80. We have several. Maybe 3 soil types (here) with the predominant making 70% of the 80. Slope will be 0-1 degree. Field would be adequately drained. Certainly not uncommon in NE IL.
So, how many points would be sampled (not probed, sampled) in zone testing? Would all zone testers choose the same number of samples? If not, is it possible to choose the wrong company to utilize zone testing?
In our typical "little squares" of 2.5 A grids, we'd have a minimum of 32 grids in that field. Surely in our 330' x 330' tests we would hit all the zones, wouldn't we? There would be no doubt.
That field would cost about $500 to have gps tested with recs & prescription files supplied for our spreader. My spreader does seem to like to spread squares. I don't have the new "half-width" disconnect now being offered. Not sure that is necessary anyway.
Covid mask effectiveness on controlling the virus certainly seems debatable. Not by true believers, but by a big % of the population that is skeptical.
JD vs IH combines is also debatable. I doubt you'll find many owners of $500,000+ combines these days saying "I don't care which I get, they're equal....".
Point is, whichever one is doing is probably OK. However, the other side of all these choices seem to chastise those that don't utilize their stance. |
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ECIL | Goose You are very passionate about your work and Im sure your clients apperiate your thoroughness. I think you are assuming my post as somehow being challenging or negative to your comments and are being way too defensive. One of the precepts of the whole precision farm industry is that soil "fertility" as measured by soil test are homogenous and repeatable inside of a relatively small area. Everyones milage may very in that regard. I have spoken to several long term precision technology users who after many years of using soil test numbers for VR fertilizer rec are moving to yield based crops removal type recommendations. I'm not sure where things go from here. Everyone has good results using soil test based VR for Ph, but personally after over 20 years on some fields in my mind P&K are still a work in progress. Yes I know I didn't do this right or I didn't do that right and there is little need to convince you otherwise but that is the trend I am seeing
Edited by garyl 10/17/2020 06:44
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Northern Nebraska | I'm. Moving to the opposite side of the spectrum making zones based on yield maps and only sampling and fertilizing the poor areas. |
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WC Mn/Dakotas | garyl - 10/17/2020 06:42
Goose You are very passionate about your work and Im sure your clients apperiate your thoroughness. I think you are assuming my post as somehow being challenging or negative to your comments and are being way too defensive. One of the precepts of the whole precision farm industry is that soil "fertility" as measured by soil test are homogenous and repeatable inside of a relatively small area. Everyones milage may very in that regard. I have spoken to several long term precision technology users who after many years of using soil test numbers for VR fertilizer rec are moving to yield based crops removal type recommendations. I'm not sure where things go from here. Everyone has good results using soil test based VR for Ph, but personally after over 20 years on some fields in my mind P&K are still a work in progress. Yes I know I didn't do this right or I didn't do that right and there is little need to convince you otherwise but that is the trend I am seeing
No I'm not taking offense. I'm very clearly asking you questions about your statements that were not clear to me or that you just alluded to. I'm curious and asking for clarification. Its hard to learn if you don't have all the details of what someone else is doing.
Much of the precision ag industry and farmers wishes is based on convenience and a lack of understanding or a misunderstanding and trying to over simplify things. I dont doubt many are going to crop removal based recs as it is easier and quicker to do than boots on the ground.
P and K is very complex if you truly understand the chemistry (and i dont, but) and crop response and you take the time to calculate it all. There are about 6 factors from a complete soil analysis that need to be analyzed to build an accurate P or K rec. Most computerized scripts use only PPM. Sometimes this gets close, but often it's off one way or the other and may be off for different reasons year to year.
Here at least, many believe fertility is homogenous, and those willing to learn are finding even on table top flat rrv single soil type fields, it is far from homogenous.
I'm not saying I know everything or doing it all right. Its a balance of many aspects and there are a number of ways above average agronomists get to similar end results. Unfortunately I see many kicking out very poor quality quick and easy precision ag and turning growers sour on the concept.
I'm just fortunate enough to know or have tracked down several industry pioneers and leaders that have helped me learn many behind the scenes details or understand the fine print of satellite imagery, statistics and scripts in software, fertility, population, etc, that many in precision ag dont know, but use the end product of someone else's work. |
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WC Iowa | Not trying to hijack the thread or put you on the spot, but would you agree with me that large unreplicated corn yield plots, say over five varieties, are worthless due to typical soil variation? |
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WC Mn/Dakotas | Haybale - 10/17/2020 12:41
Not trying to hijack the thread or put you on the spot, but would you agree with me that large unreplicated corn yield plots, say over five varieties, are worthless due to typical soil variation?
YES! Worthless
If you want to start a new thread I would explain. |
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WC Mn/Dakotas | Ron..NE ILL..10/48 - 10/17/2020 04:58
KS-Notill
This has been our experience also. Again, this may be a "here" thing. But let's say we have a 1/4 mi x 1/2 mi straight edge 80. We have several. Maybe 3 soil types (here) with the predominant making 70% of the 80. Slope will be 0-1 degree. Field would be adequately drained. Certainly not uncommon in NE IL.
So, how many points would be sampled (not probed, sampled) in zone testing? Would all zone testers choose the same number of samples? If not, is it possible to choose the wrong company to utilize zone testing?
In our typical "little squares" of 2.5 A grids, we'd have a minimum of 32 grids in that field. Surely in our 330' x 330' tests we would hit all the zones, wouldn't we? There would be no doubt.
That field would cost about $500 to have gps tested with recs & prescription files supplied for our spreader. My spreader does seem to like to spread squares. I don't have the new "half-width" disconnect now being offered. Not sure that is necessary anyway.
Covid mask effectiveness on controlling the virus certainly seems debatable. Not by true believers, but by a big % of the population that is skeptical.
JD vs IH combines is also debatable. I doubt you'll find many owners of $500,000+ combines these days saying "I don't care which I get, they're equal....".
Point is, whichever one is doing is probably OK. However, the other side of all these choices seem to chastise those that don't utilize their stance.
Everyone is going to zone differently and choose where to sample. Here is what I do and compared to a 2.5 acre grid, ssurgo soil type, Aerial image derived soil type. In this case the 80 has a ridge running through that most fields here don't have, so I sampled 4 zones instead of the more normal 3 zones. Usually I have 7 zones and sample zone 3 (zones 1 &2 are extreme low or ditch bottoms and sometimes have water standing), 5, & 7(the very best) and in this case zone 12-13 (the ridge). I dont sample points like if it were grided. I sample 2-5 cores out of an area of a zone a few feet apart. Often I take 3 cores from 4 areas of the same number zone across the field. So I'm after 12 cores that represent each zone for a total of 36 cores (or in this case 48 cores). If I were to grid, I would select a point within the grid that best represents that grid (not necessarily the middle) and then pull 10-12 cores around that point. So if grided, I would pull 320+ cores. These 48 cores take me about an hour to get, more driving and less cores per spot vs grids, so about 1.25 min per core on avg. I drive around the field 3 times basically, doing the best zone, then middle, then poor separately so there is zero chance of dropping a core in the wrong bucket. If I did grids and for arguments sake could take 2x cores in that 1.25 rate, it would take me over 3 hours to sample. Realistically, it would be about 4 hours good cores. So 4x the time/cost to grid vs zone. I do complete analysis and that costs me $26/sample, so about $100/field by zones vs ??? Less than a complete costs less, but 32 samples (so $5-??/sample x 32) 32 complete samples would be over $800. We don't typically have to lime, but if we do its 1-3 of my 7-13 zones. So were are just adjusting NPK and population I can sample every year after each crop, write accurate recs and build maps for about $10/acre per year for the same money as doing a grid once every 4 years and guessing what 4 crops are going to remove based off of 1 year grid test. I dont think anyone that grid samples for a living is going to spend 4 hours sampling an 80. That means less cores, less care for each core, etc. It means some analysis less than a complete. This all equates to less quality of a product imho.
I have attached a few pics of this field with ssurgo soil lines and 2.5 acre grids over my zones. Many of the grids have multiple soil types or multiples of my zones. Often several grids have poor, middle, and best zones in a single grid (often as many as 25-30% of grids) Thats alot of known error by forcing grids and throwing out known zones.
1st pic is ssurgo showing like 7 soil types, but in reality many are closely related, so I would say more like 3 soils.
2nd pic is aerial derived soil types. Shows quite a bit more accuracy than ssurgo based zones for those that "zone" by soils.
3rd pic is my zones with grids
4th pic is my sample points
5th is a corn yield map that is cleaned, adjusted, and then smoothed for zone purposes. 15 bu to 299 bu with field avg of 185 bushels. Again this isn't most common here with this gravelly ridge. But often we have drown out or severe wet that is less than 100 bu to zero and best zones getting 220-270 bu highs with 160-225 field averages.
6th is midwest lab results lo3 is poor, lg5 is middle, dg7 is best, rh13 is ridge.
Edited by GOOSEPILOT 10/17/2020 16:23
 (2_5 grid ssurgo soils (full).jpg)
 (2_5 grid accurate soils (full).jpg)
 (Zones w-Grids (full).jpg)
 (Zones w-z sample pts (full).jpg)
 (20201017_152414 (full).jpg)
 (Soil analysis report (full).jpg)
Attachments
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2_5 grid ssurgo soils (full).jpg (113KB - 114 downloads)
2_5 grid accurate soils (full).jpg (116KB - 107 downloads)
Zones w-Grids (full).jpg (137KB - 106 downloads)
Zones w-z sample pts (full).jpg (137KB - 99 downloads)
20201017_152414 (full).jpg (137KB - 98 downloads)
Soil analysis report (full).jpg (140KB - 103 downloads)
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Soil grids
